3 ketals and 3 enol ethers of 2-chloro 11beta, 21-dihydroxy 4, 17/20-[cis] pregnadiene-3-one and 21-acyl esters thereof



acid and -R is hydrogen or Ac glycol, trimethylene United States Patent 3 KETALS AND 3 ENOL ETHERS F Z-CHLORO 11,8,21 DIHYDROXY 4,17/20-[CIS] PREGNADI- ENE-3-0NE AND ZI-ACYL E$TERS THEREOF William P. Schneider, Alan H. Nathan, and John A. Hogg, alamazoo Township, Kalamazoo County, Mich, assignors to The Upjohn Company, Kalamazoo, Mich, a corporation of Michigan No Drawing. Application May 23, 1955 Serial No. 510,517

5 Claims. (Cl. 260-23955) This invention relates to novel 2-halogenated steroids and especially 2 chloro 11fi,17a,21 trihydrQxyl-prega process for their production. The novel compounds of the present invention and the process for their production may be represented by the following formulae:

ROOC

H R000 H H80 HaC R," R'-. on

a CH: c1 01 s O: u

I II

I Ho-oH, H R -o-on, H

\C/ 1130 I H3O I H0 H0 CH3 CH3 c1 01 IV In 1 X Ac-O-CH: H CH-O-R' HO I no CH3 CH3 o1- N 01- i wherein R is hydrogen or lower-alkyl, R isp-hydroxy or keto, R" is a ketone protecting'group, e. g., a ketal or enol ether, Ac is the 'acyl radical of an organic carboxylic as defined above.

Protecting the 3-keto group of a 2-chloro-3-keto-11- oxygenated-4,17(20)-[cis]-pregnadiene 21 -carb onyloxy steroid (I) with a keone protecting group, e. g., an enol ether or ketal group according to methods known in the art, e. g., reaction ofI with ethylene glycol, propylene glycol, methyl alcohol, ethyl alcohol, 70 benzyl alcohol, etc., in the presence of an acidic catalyst, is productive of II. Reduction of II with lithium 2,865,914 Patented Dec. 23, 1958 2 aluminum hydride, sodium aluminum hydride or equivalent chemical reducing agent capable of reducing group to a a 3 ketone protected 2 chloro 11 3,21 dihydroxy- 4,17(20) [cis] pregnadiene 3 one (III). Hydrolysis of the 3-ketone protecting group with aqueous acid is productive of 2-chloro-11,8,21-dihydroxy-4,17(20)-leis]- pregnadiene-S-one (IV). Acylation of the 21-hydroxy group prior to hydrolysis of the 3-ketone protecting group is productive of a 3-ketone-protected 2-chloro-l1p-hydroxy 2l-acyloxy-4,17(2 0)-[cisJ-pregnadiene-B-one (III, R' is Ac), which can be selectively hydrolyzed to produce 2 chloro 11p hydroxy-21-acyloxy-4,l7(20)-[cis]- pregnadiene-3-one (V). Oxidative hydroxylation of IV or a 2l-ester thereof (V) with, for example, osmium tetroxide and hydrogen peroxide, is productive of 2-chloro- 1113,17a,2l-trihydroxy-4-pregnene-3,ZO-dione (VI, R' is H) and 21 esters thereof (VI, R is Ac), respectively.

A 2 chloro-3-keto-l1-oxygenated-4,17(20)-[cisJ-pregnadiene-Zl-carbonyloxy steroid (I) is prepared as described in the copending application of Hogg, Beal, Nathan and Lincoln, S. N. 346,274, filed April 1, 1953, now Patent No. 2,790,814 e. g., by reacting ll-ketoprogesterone with about two molar equivalents of sodium methoxide and about two to ten molar equivalents ofdiethyl oxalate in tertiary butyl alcohol, followed by chlorination with about three molar equivalents of chlorine and then by rearrangementwith a small excess of sodium methoxide and methanol to produce methyl 2-chloro-3,11- diketo-4,l7(20)-[cisJ-pregnadiene-2l-oate (I; R is methyl, R is keto). Hydrolysis of this compound with sodium methoxide, in the reaction described above is productive of the free acid (I; R is H, R is keto). Substituting 11 3- hydroxyprogesteroue for the ll-ketoprogesterone as the starting steroid in the reactions described above is productive of the corresponding llfi-hydroxy steroids. Substituting another lower-alkano-l and alkali-metal loweralkoxide for the sodium methoxide and methanol employed above, e. g., sodium ethoxide and ethanol, is productive of other lower-alkyl esters of 2-chloro-3,1l-diketo- 4,17(20)-[cisl-pregnadiene-Zl-oic acid and 2-chloro-dketo-ll/3-hydroxy-4,17(20)-[cisJ-pregnadiene-Zl-oic acid which can also be prepared by esterification of the free acid, according to methods known in the art.

Substituting fluorine or iodcheptafiuoride for the chlorine employed above is productive of the corresponding 2- fluoro compound. Alternatively, the 2-chloro compounds (I to VI) can be reacted with a metal fluoride under exchange reaction conditions to produce the corresponding fiuoro compounds. These fiuoro compounds are converted to 2-fluorohydrocortisone and 2l-esters thereof in the same manner as the'corresponding 2-chloro compounds. Reacting 2 chloro-l15,21-dihydroxy-4,17(20)- pregnadiene-3-one (IV) or 2l-ester thereof (V) with sodium iodide in acetone is productive of the corresponding 2-iodo compound which is converted to 2-iodohydrocortisone and 2l-esters thereof in the same manner as the corresponding Z-chloro compounds. The 2-chloro compounds (IV to VI) are similarly converted to the 2- romo compounds which produce 2-bromohydrocortisone and 2l-esters thereof.

Oxidation of the 2-chloro-, 2-fluoro-, 2-bromoor 2- iodo-Compound VI, with N-bromoacetamide in tertiary butyl alcohol is productive of the corresponding ll-keto compounds, i. e., 2-halocortisone and 2l-esters thereof which also possess adrenal cortical hormone activity.

The Z-haIogenated cortical hormones, i. e., 2-halohydrocortisone, 2-ha1ocortisone, and 2l-esters thereof, have carbinol is productive of proved alternative for the'natural hormone in the treat-' ment of maladies in both humans and valuable domestic animals, e..g., in inflammations of the skin and eyes caused by bacterial or fungal infections, contact dermatitis or other physiological maladjustment.

The 2halogenated cortical hormones of the present invention, particularly the 2-chlorohydrocortisone and 21- esters thereof, are especially useful in pharmaceutical compositions and mixtures, e. g., ointments, lotions, greases, creams, aqueous suspensions, etc., for topical use. Incorporation of an antibiotic, especially neomycin sulfate, in an ointment, has surprising therapeutic advantages with each active ingredient potentiating and supplementing the useful properties of the other.

The following preparations and examples are illustrative of the products of the present invention and a process for their production, but are not to be construed as limiting. V

' PREPARATION 1 M ethyl 2-chl0ro-3,11-diketo-4,17(20) -[cis]- pregnariiene-ZI-oate A solution of 6.57 grams (0.02 mole) of ll-ketoprogesterone in 100 milliliters of tertiary butyl alcohol was prepared at seventy degrees centigrade in an atmosphere of nitrogen. .When the temperature of the solution dropped to 55 degrees centigrade, there was added with stirring 11.7 grams (0.08 mole) of ethyl oxalate and 2.70 grams of sodium methoxide (0.05 mole) as a 25 percent solutionin methanol, all in an atmosphere of nitrogen. Stirring was continued for about fifteen minutes while permitting the temperature to drop to about 37 degrees centigrade. A solution of 1.70 grams of glacial acetic acid and 2.46 grams of sodium acetate in 160 milliliters of methanol, cooled to ten degrees centigrade, was then added. The resulting dark green solution was cooled to about zero degrees centigrade and chlorine gas was added until the solution turned cloudy and white and a positive test for halogen on moistened fractions contained 3.37 grams of the starch-potassium iodide paper was obtained. The mixture was stirred for five minutes and, if a negative test for halogen was obtained, more chlorine was added until a positive test was obtained. This procedure was repeated until a persistent positive test for halogen was obtained. It was important, however, not to add more than just enough chlorine to give a positive test. The temperature of the reaction mixture was maintained at between zero and five degrees centigrade during the chlorination which took about forty minutes.

To the resulting halogenated mixture was added 4.536 grams of sodium methoxide as a 25 percent solution in methanol. The temperature of the reaction mixture was permitted to rise to about 25 degrees centigrade. The mixture was maintained at this temperature for two hours and then poured into 1.7 liters of a mixture of ice and water. The resulting steroidal precipitate was filtered, washed thoroughly with water, filtered and dried. The dried crude product weighed 7.67 grams and melted at 100 to 120 degrees centigrade. V The precipitate was dissolved in benzene and poured over a column of thirty grams of Florisil synthetic magnesium silicate. The column was washed with a total volume of 390 milliliters of benzene and then developed with 130 milliliters of Skellysolve B hexane hydrocarbons plus ten percent acetone. The eluate fractions containing the bulk of the crystalline material were combined to give 3.51- grams of methyl 2chloro-3,1l-diketo-4,l7- (20)-pregnadiene-21-oate melting at about 185 to 189 degrees centigrade. Recrystallization of these crystals from ethyl acetate gave colorless prisms. melting at 192 to 193' degrees centigrade, having an [@1 5 of plus 214 degrees in chloroform and the analysis below.

Calculated for C I-1 C10 C, 67.59; H, 6.96; Cl, 9.07. Found: C, 67.94; H, 6.84; Cl, 8.46.

y 4 PREPARATION 2 The 3- ethyle ne glycol ktal of methyl 2-chloro- 3,11-diket0-4,17(20)-[cis] -pregnadiene-2I-0ate A solution of 3.71 grams of methyl 2-chloro-3,11- diketo 4,17(20) [cis] pregnadiene-Zl-oate and 0.360 gram of paratoluenesulfonic acid dissolved in a mixture of milliliters of benzene and ten milliliters of ethylene glycol was refluxed for eight hours with continual removal of the water reaction by a water trap. The cooled benzene solution was shaken with aqueous sodium bicarbonate, dried and then poured over a chromatographic column of 220 grams of Florisil magnesium silicate. The column was developed with nine 300-milliliter portions of Skellysolve B plus four percent acetone and six 300- milliliter portions of Skellysolve B plus eight percent acetone. The sixth through twelfth 300-milliliter eluate 3-ethylene glycol ketal of methyl 2-chloro-3,l1-diketo-4,17(20)-[cis]-pregnadiene-Zl-oate whose melting point varied from about 147 to about 203 degrees centigrade with no apparent difierence in purity. The infrared absorption spectrum of this product was consistent with the structure. The product had an E of 11,225 and the analysis below.

Calculated for C H CIO C, 66.27; H, 7.18; Cl, 8.15. Found: C, 66.38; H, 7.35; Cl. 7.63.

PREPARATION 3 The 3-benzyl enol ether of methyl 2-chl0ra-3,11- diketo-4,1 7(20 [cis] -pregnadiene-21-0ate EXAMPLE 1 The 3-ethylene glycol ketal of Z-chloro-IIBJI- dihydr0xy-4,17(20 cis] -pregnadiene-3-0ne To a solution of 0.5 gram of lithium aluminum hydride in 75 milliliters of ether was added a solution of 1.71 grams of the 3-ethylene glycol ketal of methyl 2-chloro- 3,1 1-diketo-4,17(20) -[cisl -pregnadiene-2l-oate in thirty milliliters of benzene. The mixture was stirred for one hour and then decomposed by the addition of 2.4 milliliters of ethyl acetate followed by one milliliter of water. The ether layer was decanted and washed thoroughly with water. The dried other solution was evaporated to dryness to give 1.477 grams of the 3-ethylene glycol ketal of 2 chloro 113,21 dihydroxy-4,l7(20)-[cisl-pregnadiene-3-one melting at 156 degrees centigrade with decomposition. Recrystallization of these crystals from ethyl acetate gave product melting at 156.5 to 157.5 degrees centigrade with decomposition and having the analysis below.

Calculated for C H ClO Cl, 8.67. Found: Cl, 8.14, 87.81.

EXAMPLE 2 The 3-benzyl enol ether of Z-chIom-I 113,21- dihydroxy-4,1 7 (20) cis] -pregnadiene-3-one The 3-ethylene glycol ketal of 2-chlor0-1 lB-hydroxy-ZI- acetoxy-4,17(20)-[cis1-pregnadiene-3-0ne A solution of 243 milligrams of the 3-ethylene glycol ketal of 2-chloro-1lp,2l-dihydroxy-4,l7(20)-[cisl-pregnadiene-3-one in 1.62 milliliters of pyridine and 2.43 milliliters ofzacetic anhydride was maintained at room temperature for four hours. The solution was poured into water to give a white gum which crystallized upon trituraand melted at tion with a ten percent aqueous solution of hydrochloric acid. The crystals, upon drying, weighed 255 milligrams 130 to 134 degrees centigrade. Recrystallization of these crystals from a mixture of acetone and Skellysolve B hexane hydrocarbons gave the 3-ethylene glycol ketal of 2-chloro-11,8-hydroxy-2l-acetoxy-4,17(20)- [cisl-pregnadiene-3-one melting at 143 to 144 degrees centigrade and having the analysis below.

Calculated for C H ClO Cl, 7.86; Acetyl, 9.54. Found: Cl, 7.90; Acetyl, 9.1.

EXAMPLE 4 The 3-benzyl enol ether of 2-chl0r0-I1fi-hydr0xy-21- acetxy-4,I7 (20) [cis] -pregnadiene-3,-one

Following the procedure of Example 3, but substituting the 3-benzyl enol ether of 2-chlor0-11,8,21-dihydroxy- 4,17(20)-[cis]-pregnadiene-3-one as the starting, steroid, there is thus produced the 3-benzyl enol ether of 2-chloro- 11,8 hydroxy 21 acetoxy 4,17(20) [cis] pregnadiene-B-one.

EXAMPLE 2-chlora-J1fl-hydroxy-21 -acetoxy-4,1 7 (20)-[aislpregnadiene-3-0ne To a solution of 575 milligrams of crude 3-ethylene glycol ketal of 2-chloro-1 lfi-hydroxy-Z1-acetoxy-4,17(20)- [cisl-pregnadiene-B-onc in 4.6 milliliters of methanol was mixed with 0.05 milliliter of 5 N hydrochloric acid at room temperature for three hours. The solution was then fifteen degrees centigrade.

centigrade. A second recrystallization gave 2-chloro-11fihydroxy 21 acetoxy 4,17(20) [cis] pregnadiene- 3-one melting at 169.5 to 171 degrees centigrade, having an E of 17,200, and the analysis below.

Calculated for C H ClO C, 67.88; H, 7.68; CI, 8.71. Found: C, 66.42; H, 7.56; Cl, 7.56.

EXAMPLE 6 Following the procedure described in Example 5, 2- chloro 11 8,21 dihydroxy 4,17(20) [cis] pregnadiene-3-one is produced by the hydrolysis of the 3- ethylene glycol ketal of 2-chl0ro-1lfi,2l-dihydroxy-4,l7- (20)-[cis]-pregnadiene-3-one or the 3-benzyl enol ether of 2 chloro 115,21 dihydroxy 4,17(20) pregnadiene-3-one.

EXAMPLE 7 .Z-chloro-J1fi-hydroxy-ZI-acetoxy-4,17(20) [cis] pregnadiene-3-one A solution of 122 milligrams of 2-chloro-11fi-21-dihy droxy-4,17(20)-[cis]-pregnadiene-3-one was dissolved in a mixture of 1.5 milliliters of acetic anhydride and 2.25 milliliters of dry pyridine. The mixture was maintained at about 25 degrees centigrade for about sixteen hours.

hydroxy-21-acyloxy-4,17(20)r[cis]-pregnadiene-3-ones by esterification of the 21-hydroxy group, e. g., by reaction with the appropriate acid anhydride, in the presence of a basic catalyst such as pyridine or sodium acetate. Examples of 2-chloro-l1,8-hydroxy-21-acyloxy-4,l7(20)- [cisl-pregnadiene-3-one which can be prepared include those wherein the acyl group is the acyl radical of, for example, a lower-aliphatic acid, e. g., formic, propionic, butyric, isobutyric, valeric, isovaleric, trimethylacetic, 2- methylbutyric, S-ethylbutyric, hexanoic, diethylacetic, triethylacetic, heptanoic, octanoic, a-ethylisovaleric, a cyclic acid, e. g., cyclopropylideneacetic, cyclopentylformic, cyclopentylacetic, fi-cyclopentylpropionic, cyclohexylformic, cyclohexylacetic, fl-cyclohexylpropionic, an aryl or alkaryl acid, e. g., benzoic, 2, 3 or 4-methylbenzoic, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-dimethylbenzoic, ethylbenzoic, 2,4,6-trimethylbenzoic, 2,4,6-triethylbenzoic, cznaphthoic, S-methyI-a-naphthoic, an aralkyl acid, e. g., phenylacetic, phenylpropionic, diphenylacetic, triphenylacetic, etc.

EXAMPLE 8 Z-chloro-l1 8,17a-dihydroxy-21-acet0xy-4-pregnene- 3,20-dione.

To a solution of 267' milligrams of 2-chloro-1lp-hydroxy 21 acetoxy 4,17(2 0 [cis] pregnadiene 3- molar equivalents of anhydrous hydrogen peroxide in tertiary butyl alcohol. The mixture was maintained at about 25 degrees centigrade for eighteen hours and then mixed with 0.5 milliliter of a 0.5 N aqueous solution of one is converted to 2-chlorohydrocortisone.

EXAMPLE 9 then chilled in a refrigerator for sixteen hours. The precipitated 2-chlorohydrocortisone is filtered and dried.

2-fiuoroand 2-chlorohydrocortisone can also be prepared by substituting the corresponding 2-halo-11 8,21- dihydroxy-4,17(20)-[cis]-pregnadiene-3-one for the 21- pounds shown and described, as ObVlOUS modifications art, and the invention is therefore to be limited only by the scope of the appended claims.

- 3-enol ethers of (1) 2-chloro-11;8,2l-dihydroxy-4,17(20) -wherein R is selected from the group consisting of hydroketals thereof represented by the following formula:

and equivalents will be apparent toone skilled in the We claim: 4 1. A compound selected from the group consisting of 5 [cis]-pregnadiene-3-one and 21-acyl esters thereof represented by the following formula:

gen and the acyl radical of a hydrocarbon carboxylic '20 acid containing from one to twelve carbon atoms, inclusive, and wherein R is a hydrocarbon radical containing from one to eight carbon atoms, inclusive, (2) 3-cyclic R0'CH: H

C1 (CH2) rwherein n is a whole number from one to two,inclusive, and wherein R is selected from the group consisting of hydrogen and the acyl radical of a hydrocarbon carboxylic acid containing from one to twelve carbon atoms,

inclusive, and wherein sisting of hydrogen and hydrocarbon radicals containing I References Cited in the file of this patent UNITED STATES PATENTS 2,681,353 Archer June 15, 1954 2,684,364 Jones July 20, 1954 2,707,184 Hogg et a1 Apr. 26, 1955 2,748,150 Bergstrom May 29, 1956 2,774,775 Korman et al. Dec. 18, 1956 2,790,814 Hogg et a1. Apt. 30, 1957 OTHER REFERENCES Experientia, vol. X11, #9, pages 325-326 (1956). J. A. C. S. 76, page 1455 (1945). 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF 3-ENOL ETHERS OF (1) 2-CHLORO-11B,21-DIHYDROXY-4,17(20)(CIS)-PREGNADIENE-3-ONE AND 21-ACYLESTERS THEREOF REPRESENTED BY THE FOLLOWING FORMULA: 